A power harvester is an essential component of power grid monitoring equipment. Power grid monitoring is increasingly pursued by the power industry to improve grid reliability and to reduce liability related to outages and failures. The power harvester can be used to generate power from the existing utility grid infrastructure in order to provide power to sensors and associated equipment for the grid monitoring.
The power harvester uses inductive transformation of electrical power. Inductive transformers taking advantage of electromagnetic phenomena as described by Maxwell's equations. The most common implementation involves a transformer with a relatively fixed efficiency and thus a constant ratio of input versus output power. In that case, the delivered input (primary) power is automatically coupled to the demanded (secondary) power and this constant ratio can extend from watt to megawatt.
Accordingly, a need exists for an improved power harvester, particularly one providing relatively fixed power output over a wide range of primary line currents.